Railway-traffic-controlling apparatus



Nbv. 9 1926.

Filed Oct. 6. 1923 R. A. M CANN RAILWAY TRAFFIC CONTROLLING APPA RATUS 2 Sheets-Sheet 1 RNVENTOR 3 #ZQZ-M.

R. A. M CANN RAILWAY TRAFFIC CONTROLLING APPARATUS Nov. 9 192.6.

INVENTOR 2 IQ-Q- m a um, W'

2 Sheets-Sheet 2 Filed Oct- 6. 1923 Patented Nov. 9, 1926.

STATES 1 fi06,435 PATENT QFFEQE.

noNALn A. M'cCANN, or swissvALE, IBENIIT'SYLVANIVA, iiss'IeNon TO THE UNION swircn & sreNAn COMPANY, or SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

Application filed (icto'ber 6, i923. Serial No. 666,952.

lily invention relates to railway traffic controlling apparatus, and particularly to apparatus of the type wherein governing mechanism on a train is controlledby energy received inductively from the track rails. More particularly the present invention relates to the tracltway portion of such apparatus. I

I will describe two forms of apparatus embodying my invention, and will then point out the novel features thereof in c aims.

In the accompanying drawings, Fig. 1 is a diagrammatic view showing. one form of trackway apparatus embodying my invention, and Fig, 2 is a diagran'imatic view showing a modification ofthe apparatus shown in Fig. 1 and also embodying my invention.

Referring first to Fig. 1, the reference characters 1 and 1 designate thetrack rails of railway along which traflic normally moves in the direction indicated by the arrow. These rails are divided by insulated joints 2 into a plurality of successive sections of which only one section D-E is shown in the drawings. It is understood, however, that each section would be providedwith'apparatus similar to the apparatus associated with the section DE.

In the form here shown, the railway is of the electric propulsion type; so; that balanced inductive bonds i-l are provided to conduct the propulsion current around the insulated joints 2. y

Traci; circuit current is normally supplied to the rails at the exit end ofsection D-E by a transformer' T the secondary of which 'onstantly connected across the track rails. The primary of this transformer is provided with a circuit which passes from a wire B, through front point of contact 5 of relay F, primary of transformer T anclfront point of contact 6 of relay F to awire C. lVires li and C are constantly supplied with alternating current by a generator G. Belay F is controlled by a front contact l of a'track relay R forthe section next in advance of section D--E, so that when such section next in advance'is unoccupied relay F is energized andalternating current of what'I will term normal relative p olarity is then supplied to section D-E at the exitend of the section.

hen relay F is tie-energized track circuit current is supplied to transformer T under the control of a relay R Relay R is provided with a windingQt which receives energy fromthe track rails through a trans former T the primary of which is connecte dacross the rails at an intermediate point K in the section D-E. This point K is located at substantially maximum braking distance in the rear of point E for trains movinglat a medium speed, such as8-5 miles per hour, As here shown, relay R is provided with a second winding 25 which re ceives energy from the track. rails at the exit end E of section'DE. Both windings 24: and 25 must receive energy in order to energize relay R i l/hen relay R is energized and relay F is de-energized, the primary circuit for transformer T passes from wire B, through front point of contact 10 of relay R back point of contact 6 of relay F, primary of transformer T back contact 5 of relay F, and front point of contact 9 of relay R to wire C. When this circuit is closed, current of what I will term reverse relative polarity is supplied to the rails of section DE at theexit end of the section.

Located adjacent the entrance end of section DE is a slow-releasing relay L, the circuit for which passes from wire L through the back point of contact lO of relay R back point of contact Scf relay F and windingof relay L to wire C. Relay L is therefore normally de-energized and is energized only when both relays R and F are de energiZed. a

Also located atthe entrance end of section D-E is a track relay R having two windings 17 and 18. Winding 17 is connected across the track rails in series with an impedance 16, whereas winding 18 is normally supplied with current in a mannot which will be explained hereinafter. Whenrelay L is de-cnergized, the impedance 16 is shunted through back contact 21, so that this impedance has noeflect on the track circuit current supplied to relay winding 17. When relay L is energized;however, its back contact 21 is opened so that impedance 16 is effective to limit the amount of current supplied to relay winding 17.

Also located at" the entrance end of section D- E-is a transformer T the second ary of which is connected across the rails of the section. lVhen relay L is (lo-energized, the primary circuit for transformer T is opened at contact 23, but when relay L is energized, current is supplied to the primary o'l transformer 1" through a circuit which passes from wire B, through contact 2-3 of relay L and the primary of trantormer T to wire C. The current which is then supplied to the track rails is of reverse relative polarity.

The supply of current to winding 18 relay ll is controlled by relay L and by pole-changing relay P. Pole-changing relay P is controlled by contact 7 of relay F, so tlnt relay 1 is energized when relay F energized, and de-energized when relay 1* is ale-energized. lVhen relay P is energized and relay L is tie-energized, the circuit for winding 18 is from wire B. through front point of contact 19 of relay P, back contact 22 of relay L, winding 18 and front po nt of contact 20 of relay P to wire C. The

current which is then supplied to winding 18 is of normal relative polarity. When relay P is deenergized and relay L is deenergized, the circuit for winding 18 is the same as before except that the current supplied to this winding is of reverse relative polarity due to the pole-changing action of contacts 19 and 20 ot relay 1. l/Vhen relay L is energized, winding 18 is, o1 course, deenergized.

The reference character M designates a transformer the primary of which is connected across the wires B and C, and the secondary of which is connected with the middle points of the two inductive bonds 3 associated with section D-E. It will be seen, therefore, that the alternating current supplied by transformer M passes through the two track rails 1 and 1 of section DE in multiple, and that the supply of this cur rent is constant. The current supplied by transformer M, I will term local current.

Before explaining the operation of the apparatus, it should be pointed out that the traclrway apparatus herein shown is intended for cooperation with train-carried mechanism so designed that when a train receives track circuit currentof normal relative polarity and also local current, a proceed indiq cation is given on the train; when the train receives track circuit current of reverse relative polarity and also local current, a caution indication is given-n the train; and when the supply of track circuit current is discontinued, a stop indication is 'iven on the train.

As shown in the drawing, the apparatus is not affected by the presence of trains, so that track circuit current of normal relative polarity is supplied to the rails at the exit end of the section by transformer T A train passing through the section in the direction indicated by the arrow will theretore receive tracl-z circuit current of normal relative polarity and also local current throughout the section, and so a proceed in dication will be given aboard the train. ii such train enters section DE it will de-energize relay R, and as bllQ train approaches point K it will also de-energize relay R but neither of these relays will have any eli'ect on the other parts of the apparatus. As the train passes point E it will place signal S at stop, and will cause relay ll to become deenergized thereby opening the normal primary circuit for transformer T Relays and B being (lie-energized, relay L will bccome energized through back contact 8 of relay F and back contact of relay l and current will then be supplied to the primary of transformer T through contact of relay L. This current will energize relay R whereupon the auxiliary primary circuit for transformer T will become closed through contacts 9 and 10 of relay R and back contacts 5 and 6 of relay F, so that track circuit current of reverse relative polarity will be supplied to the rails of section D-E at the exit end of this section. lit the same time pole-changing relay 1 vil l, become (lo-energized due to the opening of contact 7 of relay F, so that current of reverse relative polarity will be supplied to winding 18 of relay R, whereby the currents in the two windings 17 and 18 of relay R are of the same relative polarity and the relay will therefore be energized.

I will now assume that the first train re mains in the section immediately to the right of point E, and that a second train enters section DE. As soon as such second t *ain entersthe section it will receive track circuit current of reverse relative polarity, so that a caution indication will be given aboard the train. As the second train approaches point K it will cause relay P to become ale-energized, thereby opening the auxiliary primary circuit for transformer T so that the supply of track circuit current to the rails at the exit end of the section will be discontinued. It follows that a stop indication will be given aboard the second train from the point at which this train causes relay R to open. Inasmuch as relays R and F are now both (lo-energized, relay L will become energized, thereby closing the primary circuit for transformer T, opening the circuit for track relay winding 18, and opening the shunt around impedance 16 in the circuit for relay winding 17. Track circuit current 01 reverse relative polarity is then supplied to the track rails at the entrance end of section D-E, but winding 17 of track relay R is protected from overenergrization by impedance 16. As the second train passes out of section DE track relay li will become energized by track circuit current supplied from transformer T and the closing of relay R will cause relay L to become tie-energized. The opening of rel, y L opens the primary circuit for transformer T, closes the shunt around impedance 16, and also closes the circuit for relay winding 18. Track relay B being energized, current of reverse relative polarity is again supplied to the track rails by transformer T so that track relay R becomes energized. lVhen both trains pass out of the section immediately to the right of section D-E relay F again becomes energized, so that track circuit current of normal relative polarity is again supplied to the rails of section D-E, and all parts of the apparatus associated with this section are restored to their normal conditions.

While the first train is in the section to the right 01": point E and the second train is between points K and E, relay R cannot become energized because track circuit current from T is shunted away from winding 25 by the wheels and axles of the second train.

Referring now to Fig. 2, the apparatus shown in this view is the same as that shown in Fig. 1, except that the track relay R at the entrance end of section DE is of a single winding type, and except that con tact 21 of relay L opens the circuit for relay R instead of opening a shunt around an impedance in this circuit as inFig. 1. That is to say, one terminal of relay R is directly connected with the upper track rail 1, whereas the other terminal is connected with the lower track rail 1 through back contact 21 of relay L. When relay L is energized so that track circuit current is supplied to the rails by transformer. T, track relay R is disconnected from rail 1, so that this relay is protected from over-energization. Inasmuch as the second winding is omitted from relay R, the poleechanging relay 1? is likewise omitted.

The operation of the apparatus shown in Fig. 2-, will be understood from the explanation hereinbefore given of the operation of the apparatus shown in Fig. 1.

Apparatus embodying my invention is particularly well adapted for application to electrified roads of an automatic train control system of the type wherein two currents are normally supplied to the track rails and the supply of one current is discontinued at an intermediate point of a section in the rear of an occupied section. The two currents referred to are the track circuit and the local current, the former of which flows through the track rails in series and the latter oi? which flows through the track rails in multiple. On electrified roads it is undesirable to break the circuit for the local current at an intermediate point in the section. and it is also undesirable to insert insulated joints at such intermediate point for the purpose of breaking the track circuit current. One feature 'of my invention is the provision of means for discontinuing the supply of track circuit current between points K and E in the rear of an occupied section without necessitating insulated joints in the track rails at the point K.

Although I have herein shown and described only two forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within. the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a section of railway track, means operating when the track ahead of said section is unoccupied to supply track circuit current to the rails at the exit end of the section regardless of traffic conditions in the section, and means operating when the track ahead of said section is occupied to supply track circuit current to the rails at the exit end of the section under the control of traffic conditions within the section.

2. In combination, a section of railway track, means operating when the track ahead of said section is unoccupied to supply traclc circuit current of one relative polarity to the rails at the exit end of the section regardless of traffic conditions in the sect-ion, and means operating when the track ahead of said section is occupied. to supply track circuit current of the other relative polarity to the rails at the exit end of the section under the control of traffic conditions within the section.

3. In combination, a section of railway track, a relay controlled by traiiic connitions ahead of said section, means operating when said relay is energized to supply track circuit current to the rails at the exit end of the section, a second relay receiving energy from the rails at an intermediate point in said section, and means for supply ing track circuit current to the rails at the exit end of said section when said first relay is de-energized and said. second relay is energized. I

4. In combination, a section-0t railway track, means for supplying track circuit current across the rails at the exit end. of said section, and means operating to discontinue such current supply when a train passes an intermediate point in said section and the track ahead of the section is occupied.

"5. In combinatioma section of railway track, a relay controlled by traiiic conditions ahead of said section. means operating when said relay is energized to supply track circuit current to the rails at the exit end of the section, a second relay receiving energy from the rails at an intermediate point in said section, means for supplying track circuit current to the rails at the exit end of said section when said first relay is de-energized and said second relay is energized, and means operating when both of said relays are de-energized to supply track circuit current to the rails at the entrance end of the section.

6. In combination, a section of railway track, means operating when the track ahead of said section is unoccupied to supply track circuit current to the rails at the exit end or the section regardless of tratlic conditions in the section, means operating when the track ahead of said section is occupied to supply track circuit current to the rails at the exit end of the section under the control of tratfic conditions within the section, and means operating to supply track circuit current to the rails at the entrance end or said section when the track ahead of the section is occupied and a train is beyond an intermediate point in the section.

7. In combination, a section of railway track, means for supplying track circuit current to the rails at the exit end or said section, means operating to discontinue such current supply when a train passes an intermediate point in said section and the track ahead of the section is occupied, and means for supplying track circuit current to the rails at the entrance end of said section when the supply at the exit end is discontinued.

8. in combination, a section of railway track, means operating when the track ahead of said section is unoccupied to supply track circuit current of one relative polarity to the rails at the exit end of the section regardless of trailic conditions in the section,

means operating when the track ahead of said section is occupied to supply track circuit current of the'other relative polarity to the rails at the exit end of the section under thecontrol of tra'tiic conditions within the section, and means for supplying track circuit current of the last-mentioned relative polarity to the rails at the entrance end of the section when the track ahead of the section is occupied and a train occupies the section between an intermediate point and the exit end of the section.

9. In combination, a section of railway track, means for supplying track circuit current to the rails at the exit end of the section, and means operating when a train passes an intermediate point in said section and the track ahead of the section is occupied to discontinue such current supply and to supply current to the rails at the entrance end of the section.

10. In combination, a section of railway track, a relay controlled by tratiic conditions ahead of said section, means operating when said relay is energized to supply track circuit current of one relative polarity to the rails at the exit end-of the section, a second relay receiving energy from the rails at an intermediate point in said section, means for supplying track circuit current of the other relative polarity to the rails at the exit end of said section when said first relay is de-energized and said second relay is energized, and means for supplying track circuit current of the last-mentioned relative polarity to the rails at the entrance end or" said section when both of said relays are deenergized.

11. In combination, a section of railway track, a relay cont-rolled by trailic conditions ahead of said section, means operating when said relay is energized to supply track circuit current to the rails at the exit end of the section, a second relay receiving energy from the rails at an intermediate point in said section, means for supplying track circuit current to the rails at the exit end of said section when said first relay is de-energized'and said second relay is energized, a third relay normally de-energized but energized when the first and second relays are both t le-energized, and means operating when said third relay isenergized to supply track circuit current to the rails at the entrance end of said section.

1 In combination, a section of railway track, means operating when the track ahead of said section is unoccupied to supply track circuit current to the rails at the exit end of the sectionregardl-ess of traii'ic conditions in the section, and means operating when the track ahead of said section is occupied to supply trackcircuit current to the rails at the exit end of the section or to discontinue suchsupply depending on trai- "fic conditions within the section.

13. In combination, a section of railway track, means for supplying track circuit current to the rails'at the exit end of said section, and means operating to discontinue such current supply when a train passes an intermediate point in said section and the track ahead of the section is occupied.

let. in combination, a section of railway track, both track rails of which are electrically continuous throughout the length of the section, means for supplying track circuit current across the rails at the exit end of the section when the track ahead of said section is unoccupied. and means operating when the track ahead of said section is occupied to supply track circuit current across the rails at the exit end of the section under the control of trailic conditions within the section.-

15. In combination, a section of railway track, means operatingwhen the track ahead of said section is unoccupied to supply track circuit current of one relative polarity tothe rails at the exit end of the section, means operating when the track ahead of said section is'occupied to. supply track ill to the rails at the exit end of the section under the control of traffic conditionswithin the section, track relay having two windings one of which receives energy from the track rails at the entrance end of the section, and means for supplying the other winding of said relay with current of the same relative polarity as that supplied to the rails at the exit end of the section.

16. In combination, a section of railwav track, a relay controlled by trafiic conditions ahead of said section, means operating when said relay is energized to supply track circuit current of one relative polarity to the rails at the exit end of the section, a second relay receiving energy from the rails at an intermediate point in said section, means for supplying track circuit current of the other relative polarity to the rails at the exit end of said section when said first relay is de-energized and said second relay is en ergized, a track relay having two windings one or" which receives energy from the rails at the entrance end of said section, a polechanging relay controlled by the first-mentioned relay, and means controlled by said pole-changing relay for supplying current to said second winding of the same relative polarity as that supplied to the track rails.

17. In combination, a section of railway track, means operating when the track ahead of said section is unoccupied to supply track circuit current to the rails at the exit end of said sect-ion, a relay having two windings oneot which receives energy from the rails at an intermediate point in said section and the other of which receives energy from the rails at the exit end of tie section, means for supplying track circuit current to the rails at the exit end of said section when the track ahead of the section is occupied and said relay is energized, and means for supplying track circuit current to the rails at the entrance end or said section when the track ahead of said section is occupied and said relay is tie-energized.

18. In combination, a section of railway track, means operating when. the track ahead of said section is unoccupied to supply track circuit current to the rails at the exit end of said section, a relay having two windings one of which receives energy from the rails at an intermediate point in said section and the other of which receives energy from the rails at the exit end of the section, and means for supplying track circuit current to the rails at the entrance end of said section when the track ahead of said section is occupied and said relay is tie-energized.

19. In combination, a section of railway track, a relay having two windings one of which receives energy from the rails at an intermediate point in said section and the other of which receives energy from the rails at the exit end of the section, and means controlled by said relay for supplying train governing current to the rails of said section.

20. In combination, a section of railway track, a. relay having two windingsone or" which receives energy from the rails at an intermediate point in said section and the other of which receives energy from the rails at the exit end of the section, and means controlled jointly by said relay and by tratfic conditions in advance of said sec tion for supplying train governing current to the rails of said section.

21. In combination, a section of railway track, a relay having two windings one of which receives energy from the rails at an intermediate point in said section and the other of which receives energy from the rails at the exit end of the section, and means operating to supply train governing current to the rails at the entrance end of said section when said relay is dye-energized and the track ahead of the section is occupied.

22. In combination, a section of railway track, a relay receiving energy from the rails at. an intermediate point in said section, and means controlled by said relay for supplying train governing current to the rails of said section.

28. In combination, a section of railway track, a relay receiving energy from the rails at an intermediate point in said section, and means controlled jointly by said relay and by traflic conditions in advance of said section for supplying train governing current to the rails of said section.

24-. In combination, a section of railway track, a relay receiving energy rrom the rails at an intermediate point in said section, and means operating to supply train governing current to the rails at the entrance end of said section when said relay is tie-energized and the track ahead of the section is occupied. I

25. In combination, a section of railway track, means for supplying the rails of said section with alternating current of one relative polarity or the other, a relay having two windings one of which receives energy from the rails of said section, and means for supplying the other winding of said relay with alternating current of the same relative polarity as that of the current supplied to the rails of said section.

26. In combination, a section of railway track, means for supplying the rails of said section with alternating current of one relative polarity or the other, a relay having two windings one of which receives energy from the rails of said section, means for supplying the other winding of said relay with alternating current of the same relative polarity as that of the current supplied to the rails of said section, and traflic governing means controlled by said relay.

27. In combination, a section of railway tack, means controlled by traflic conditions in advance of said section for supplying alternating current of one relative polarity or the other to the rails of said section, a relay having two windings one of which receives energy from the rails of said section, 1

and means controlled by traflic conditions in advance of said section for supplying the other winding of said relay with alternating current of the same relative polarity as that of the current supplied to the rails of said section.

In testimony whereof I atlix my signature RONALD A. MGCANN. 

